Fig. 4: Role of the CRISPR systems in anti-phage responses.
From: The coordination of anti-phage immunity mechanisms in bacterial cells
A Within-cell dynamics of slow phage infections in bacterial cells with and without CRISPR systems (as simulated by Model 3 and Model 2, respectively). The activation of CRISPR nucleases in an infected bacterial cell increases the rate of phage DNA degradation. This does not affect some phages that can still cause sustained infections of their host (1). In other cases, the increase in the rate of DNA cleavage due to CRISPR nucleases can entail the end of the infection of the bacterial cell (2). In this case, the CRISPR system could allow bacterial cells to eliminate slow phages that would otherwise escape the control of nucleases. B Numerical simulations of Model 3 in the region of the infection space corresponding to slow phages. The CRISPR response creates a new region in the infection space where slow phages can now be neutralized (shown in orange). However, some slow phages can still evade the action of CRISPR spacers and maintain the infection of the cell (yellow region). C Regions occupied by different anti-phage immune mechanisms in the infection space of a bacterial cell according to the models used in this work. The details of the simulations are provided in the “Methods” section.
